In recent years, display devices have been remarkably developed, and various display devices such as a liquid crystal display device or an EL display device have been actively introduced into OA instruments such as a computer, flat television sets, and others. These display devices each have, as a basic structure, a sandwich structure wherein a display element is sandwiched between transparent conductive films.
As switching elements for driving these display devices, elements each using a thin film are widely used from the viewpoint of downsizing or others.
Hitherto, the thin film has been technically investigated about the composition thereof, the production process thereof, and others since the film produces a large effect onto the performance and the production process of the switching elements.
Thin Film in the Prior Art
As the switching element for driving display devices at present, elements using a silicon based semiconductor film are the main current. This is because the stability and the workability of the silicon based thin film are good and additionally the elements have a large switching speed and other good performances. This silicon based thin film is generally produced by chemical vapor deposition (CVD).
As an element better in stability than the silicon based thin film, a transparent semiconductor thin film is suggested. Such a semiconductor thin film is described in, for example, Patent Document 1 described below.    Patent Document: Japanese Patent Application Laid-Open No. 2004-119525